This project proposes to investigate the following: 1) The metabolic function(s) of polygammaglutamyl derivatives of folic acid. The objective of these studies is to gain an understanding of the relationships between chain lengths in the polyglutamates of folic acid and one-carbon metabolism. 2) The metabolism of polygammaglutamyl derivatives of methotrexate in rats. Studies will be conducted designed to provide insight into the function and chemotherapeutic potentials of these in vivo formed metabolites. BIBLIOGRAPHC REFERENCES: Poly-gamma-glutamyl chain lengths in some natural folates and contributions of folic acid synthesized by intestinal microflora to rat nutrition. Charles M. Baugh, Eleanor Braverman and M.G. Nair. Proceedings of the Vth International Pteridine Symposium, Konstanz, Germany (1975). Ed., Wolfgang Pfleiderer. Walter de Gruyter, Inc., N.Y. New folate analogs: alterations in the C to the 9th power - N to the 10th power region. M.G. Nair and Charles M. Baugh. Proceedings of the Vth International Pteridine Symposium, Konstanz, Germany (1975). Ed., Wolfgang Pfleiderer. Walter de Gruyter, Inc., N.Y.